The keycaps doesn't sink instantly, at least if you don't give them a decent push.
The keycap is not textured, is totally smooth and slippery, but not as slippery as ABS. It doesn't have any sign of yellowing.
The printing (see pictures) I think it may be dye-sub. It is totally smooth printing, is obviously not pad printing and doesn't have any texture like laser infill does.
http://s345.photobucket.com/user/ancoak/library/Do not pay attention to this keys:
Enter and Spacebar keys from Blackwidow (ABS)
Tab key replacing backslash key from BTC-53 (ABS) and keys in place of FN and AppsKey, BTC-53 too (ABS)
